1. Field of the Invention
This invention relates to the attachment of plows and the like to vehicles, such as trucks and the like.
2. Description of the Prior Art
It is conventional to mount snowplows and the like to the front of a drive vehicle, such as a truck, by connecting a rear frame portion of the plow to an attachment portion on the truck. The attachment portion is conventionally elevated and it is necessary to utilize substantial forces in making the connection of the frame to the attachment. Because of the inherent difficulty in making such attachment, a number of workers are normally required to effect the attachment.
A number of devices have been developed in the background art for positioning of elements relative to a vehicle. Illustratively, in U.S. Pat. No. 2,637,449 of Clarence F. Hamer, a transmission jack is shown for installing and removing heavy parts from the underside of automobiles, trucks, tractors, etc. The jack is arranged to be rolled under the portion of the vehicle which it is desired to remove. The jack is then elevated by manipulation of a handwheel so as to adjust the position of a table which, after the part is disconnected from the vehicle, is lowered, permitting the jack to be rolled from under the vehicle with the part carried thereon.
An extensible and foldable hand truck is shown in U.S. Pat. No. 2,716,557 of Charles L. Gould et al to include a wheeled frame having an upstanding front handle portion. The load is placed directly on the platform and illustratively comprises boxes placed thereon in stacked relation so as to be engaged against the handle structure. The hand truck is arranged to be tilted backwardly to elevate the front caster wheel over obstructions which may be encountered during the movement thereof.
Noral A. Nelson shows, in U.S. Pat. No. 2,826,430, a tractor-implement coupling mechanism which may be engaged or disengaged by maneuvering the tractor relative to the implement and utilizing a power actuated rear hitch under the control of the operator on the tractor. The coupling mechanism is engaged upon powered elevation of the rear hitch mechanism for the tractor to eliminate the need for rear jack means on the implement frame. The patentee further describes a copending application structure wherein the implement frame is supported by front and rear retractable jack elements, permitting the tractor to be backed up so that a coupling element at its rear portion underlies a cooperating coupling element on the jack frame. After arranging the tractor in this manner, the operator gets off the tractor and lowers the rear jack stand until the coupling element is engaged. After making the connection, the front jack stand is also retracted to permit the implement to be connected for propulsion.
In U.S. Pat. No. 3,159,917, Stewart E. Whitehead shows a visual aid for a trailer hitch which may be removably mounted on a vehicle and on a trailer to indicate to the driver of the vehicle when the interlocking portions of the trailer hitch on the vehicle and trailer are in vertical alignment.